Recently, in a system using radio communications terminals such as mobile telephones and smartphones, a voice communications service employing a voice over internet protocol (VoIP) and the voice communications service such as Skype (registered trademark) employing a peer-to-peer (P2P) technology are provided. Among the radio communications terminals is a terminal capable of connecting with both of a mobile telephone network such as a 3rd generation (3G) line and a wireless local area network (WLAN).
One conventional radio communications terminal has been designed to set according to an operation state of an application running on the radio communications terminal, the interval at which a beacon from an access point is received (see, e.g., Japanese Laid-Open Patent Publication No. 2004-128949). There is a method in which the access point calculates a beacon transmission period, changes the beacon transmission period to the calculated transmission period, and transmits the beacon with the changed transmission period (see, e.g., Japanese Laid-Open Patent Publication No. 2010-147672). According to this method, the beacon reception interval of the radio communications terminal becomes the beacon transmission interval of the access point. There is a radio communications terminal that receives the beacon transmitted by the access point, obtains a maximum listen interval from the beacon, and sets the maximum listen interval as the beacon reception interval (see, e.g., Published Japanese-Translation of PCT Application, Publication No. 2009-529299).
The radio communications terminal described above capable of connecting with plural networks can connect with either network and perform voice communication with the counterpart call destination radio communications terminal through a voice communications service such as VoIP and Skype. In the case of connecting with the WLAN to receive the voice communications service, the radio communications terminal can respond to a received call during a standby state by constantly remaining in a state capable of communicating with the access point, i.e., a WLAN wireless station. The radio communications terminal can maintain the state of being capable of communicating with the access point by constantly receiving the beacon transmitted by the access point.
During the standby state, if the radio communications terminal is to receive the beacon at the transmission interval of the access point, a transceiver for the WLAN has to operate frequently, arising in a problem that power consumption is increased during the standby state. On the other hand, during the standby state, if the radio communications terminal is to receive the beacon at a maximum listen interval, the beacon reception interval is too long and therefore, a delay is caused in the timing of notifying a user of a received call when there is a call is received during the standby state. For this reason, there is a problem in that it is possible that the user cannot respond to the received call.